Milpitas, Calif.— Linear Technology's LTC3828 is a dual step-down switching controller with integrated tracking for sequencing multiple voltage rails, a phase-locked loop (PLL) for precision synchronization, and PolyPhase operation for reducing input capacitance and noise. The chip, which enables the design of compact multiple output power supplies in applications such as single-board computers, industrial equipment, automotive electronics and FPGA-based systems, can daisy chain to multiple LTC3828s or other DC/DC converters to provide tracking for more than two voltages while operating at 3, 4 or 6 phases. Working at 550 kHz in a constant frequency current mode, the chip can also be locked to a 260 kHz to 550 kHz clock to reduce EMI at sensitive frequencies.
The LTC3828, operating in a synchronous architecture, derives two regulated output voltages (adjustable from 0.8 volt to as high as 99% of the value of the input voltage) from a 4.5- to 28-volt input. Its two control channels operate 180 degrees out of phase. Its clock output pin enables synchronization of multiple controllers. The IC allows the user to program how the channel outputs ramp up and down. It supports both coincident and ratiometric tracking. The chip supports powering difficult loads such as those with pre-biased outputs (common with power ASICs).
The LTC3828, offered in 28-lead SSOP and 5-by-5 mm QFN packages, is rated for operation over -40 to 85°C. It's priced starting at $4.65 each in 1k quantities. The device data sheet is available at www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1042,C1032,C1092,P11132,D7937
Linear Technology, 1-800-4-LINEAR, www.linear.com